Project description:Infectious bursal disease virus (IBDV) is a highly contagious dsRNA virus (Birnaviridae) which causes immuno-suppression in chickens. Although largely controlled by vaccination, new, virulent strains of the virus mean that infectious bursal disease (IBD or ëGumboroí disease) still remains a threat to the poultry industry. The virus infects dividing IgM+ B-lymphocytes and the main site of viral replication is the bursa of Fabricius where B cells are produced. Infection is spread orally via contaminated feed and water. IBDV affects young birds, with the disease usually being diagnosed in 3-6 week old birds. Younger birds do not show clinical signs but are immuno-suppressed. Symptoms include anorexia, depression, diahorrea, ruffled feathers, immuno-suppression and bursal lesions. The disease peaks between 2-5 days post infection and is practically cleared by day 7. Mortality is variable but can be up to around 70% with very virulent strains of the disease. Even if birds survive, the resulting immuno-suppression and effect on egg production in layer birds is significant. Being able to breed commercial lines of birds for enhanced genetic resistance to IBDV is an obvious goal in the fight against the disease. Three-week-old chicks were inoculated with virus via an intra-nasal route and tissue samples were collected at 2, 3 and 4 days post-inoculation. Bursa and spleen tissues were examined from control and infected birds at 2, 3 and 4 days post-infection in birds known to be either susceptible or resistant to the virus. As well as understanding the host immune response to IBDV, we are interested in identifying genes involved in disease resistance and so we have analysed the gene expression profiles at these times, when the innate immune response is active. We assume that genes underlying resistance will be involved at this early stage of the host immune response.
Project description:Viral diseases pose major threats to humans and other animals, including the billions of chickens that are an important food source as well as a public health concern due to zoonotic pathogens. Unlike humans and other typical mammals, the major histocompatibility complex (MHC) of chickens can confer decisive resistance or susceptibility to many viruses. Examples are Marek's disease virus (MDV) and Infectious bursal disease virus (IBDV). We used a new in vitro infection system and immunopeptidomics to identify peptides presented to T lymphocytes via classical MHC class II molecules.
Project description:Transcriptomics analysis reveals that severity of infectious bursal disease in White Leghorn inbred chicken lines is associated with greater bursal inflammation in vivo and more rapid induction of pro-inflammatory responses following ex vivo stimulation of primary bursal cells. In order to better understand differences in the outcome of infectious bursal disease virus (IBDV) infection, we inoculated very virulent (vv) IBDV into White Leghorn chickens from inbred line W that previously had over 24% mortality, and three inbred lines (15I, C.B4 and O) that previously had 0% mortality. Within each experimental group, some individuals experienced more severe disease than others but line 15I birds experienced milder disease based on average clinical scores, percentage of birds with gross pathology, average bursal lesion scores and average peak bursal virus titre. RNA-Seq analysis revealed that more severe disease was associated with a significant up-regulation of pathways involved in inflammation, cytoskeletal regulation by Rho GTPase, nicotinic acetylcholine receptor signaling, and Wnt signaling in the bursa. Primary bursal cells cultured from line W birds and stimulated ex vivo with LPS had a more rapid up-regulation of pro-inflammatory gene expression than cells from line 15I birds, and line W birds had a significantly greater percentage of KUL01+ macrophage cells in the BF than line 15I birds. We hypothesize that a more rapid induction of pro-inflammatory cytokine responses in line W birds causes excessive inflammation and clinical disease following IBDV infection compared to line 15I, and we suggest that pro-inflammatory pathways could be targeted to engineer more disease resistant birds in the future
Project description:We used a chicken immune-targeted gene array to analyse the differences in gene expression in the bursa of Fabricius from genetically resistant and susceptible animals infected with Infectious Bursal Disease Virus (IBDV).
Project description:H5N1 subtype highly pathogenic avian influenza virus has been spreading to Asia, Eurasia and African coutries. An original or six of recombinant H5N1 subtype influenza viruses with varying survivability were infected to chickens for elucidating genes correlated with pathogenicity. Two chickens were infected with each 10^6EID50/ head virus intranasally, and their lung was collected from infected chicken at 24 hours after infection.
Project description:H5N1 subtype highly pathogenic avian influenza virus has been spreading to Asia, Eurasia and African coutries. An original or six of recombinant H5N1 subtype influenza viruses with varying survivability were infected to chickens for elucidating genes correlated with pathogenicity.
